System and method for transferring airplanes

ABSTRACT

A method for transferring airplanes and an unmanned airplane transfer system. The airplane transferring system includes: receiving a transfer signal responsive of a movement of an airplane control component; and transferring an airplane, by an unmanned airplane transfer system, in response to the transfer signal.

FIELD OF THE INVENTION

The present invention relates to systems and methods for transferringairplanes.

BACKGROUND OF THE INVENTION

In modern airports the terminal is located relatively far from therunaways. Airplanes use their jet engines to travel from the terminal toa runaway (said operation is also known as taxi-out) and to travel froma runway to the terminal (said operation is also known as taxi-in).

These jet engines are very noisy, cause safety hazards, burn largequantities of fuel and cause to significant air pollution, the emissionof large quantities of CO₂.

Taxi traffic delay is the largest of all aviation movements delay, theaverage taxi-out delay in minutes per flight is approximately twice theairborne delay. Although aircraft burn roughly 5 times faster whenairborne, crew and equipment costs make the spend rate for taxiingaircraft about ⅔ that for airborne aircraft. Consequently, the cost oftaxi-out delay exceeds that of airborne delay by about ⅓, totaling morethan 1 B$ annually. By automated tower controlled ground movement, oneshall save significantly on taxi delays, which make significant annualcost. This shall add to the savings from fuel burned during taxiperformed by towing tractors or robots.

Jet fuel is one of the two largest airlines operating expenses (theother being labor cost), constituting 25-30% of typical airline annualoperation cost. Therefore, saving in fuel consumption is one of themajor efforts for all airlines today. Jet fuel prices increased fromless than 1$/gal in 2001 to 2$/gal in 2006 and is expected to reach 2.5$/gal or higher by 2010, making the issue critical for the airlineindustry.

During taxi, typical aircraft fuel consumption is about 3200 lbs perhour (9.0 gallon per minute). Typical taxi-out time today is 30 minutesand rising constantly with the increase of air traffic all over theworld. On average, typically, taxi-out time is 3 times longer thantaxi-in time. Thus, a minimum of 40 minutes of taxi-out plus taxi-intime burn 360 gallons of fuel on airport grounds per flight, and thisnumber is growing.

Air pollution in airports evolved into a major and significant hazard,and it keeps evolving due to the increment in air traffic worldwide. Gasemission in a jet engine is around 8 Kg of CO₂ per gallon. In a typical40 minutes taxi-out plus taxi-in time, an aircraft emits 2.9 ton of CO₂,a very critical issue.

By 2010, the forecast is of more than one billion (1 B) air travels, oraround fifteen million (15 M) flights a year, only in the US, notrelating to the worldwide air traffic. For every 100 gallon of fuelsaved during taxiing per flight, it is about 3.0 B$ in fuel and 12 M tonin CO₂ emission, in the US.

A typical busy airport has more than 1000 departures a day or around400,000 flights a year. Every 100 gallon of fuel saved per flight,transfers in 40 M gallon fuel saved per year per airport, or 80 M$yearly savings in fuel expenditure per airport (2$/gal today), actualsavings being much higher.

In order to reduce the usage of jet engines various airplane towingsystems were provided. Some are illustrated in the following patents andpatent applications, all being incorporated herein by reference: U.S.Pat. No. 6,305,484 of Leblanc; U.S. Pat. No. 5,219,033 of Pollner etal.; U.S. Pat. No. 5,314,287 of Wichert; U.S. Pat. No. 5,860,785 ofEberspacher; U.S. Pat. No. 6,283,696 of Trummer et al.; U.S. Pat. No.6,352,130 of Klein et al.; U.S. Pat. No. 6,543,790 of Johnson; U.S. Pat.No. 6,675,920 of Diez et al.; U.S. Patent application publication serialNo. 2006/0056949 of Eckert; U.S. Patent application publication serialNo. 2003/095854 of Abela; U.S. Patent application publication serial No.2005/196256 of Rodenkirch et al.; European patent application 649787A1of Michelson et al and PCT patent application publication serial numberWO/04028903A1 of Maggiori.

There is a need to provide an efficient method and system fortransferring an airplane.

SUMMARY OF THE PRESENT INVENTION

An unmanned airplane transfer system is provided. The system includes atransfer module adapted to transfer an airplane, and a controller,coupled to the transfer module, adapted to receive a transfer signalresponsive of a movement of an airplane control component and inresponse control the transfer module.

Conveniently, the unmanned airplane transfer system includes a sensoradapted to sense a steering control induced movement of the landing gearand in response provide a transfer signal to the controller.

Conveniently, the system is adapted to sense a movement of the airplanecontrol component.

Conveniently, the steering commands are sensed by a sensor adapted tosense control induced movements of the landing gear.

Conveniently, steering commands are obtained either directly orindirectly from at least one airplane control component (such as aflight control stick, throttle, pedal, steering wheel) and the airplaneis transferred in response to these steering commands. An airplanecontrol component can affect the airborne or ground movement of theairplane, especially when the airplane can autonomously move.

Conveniently, the unmanned airplane transfer system includes: (i) atransfer module adapted to support a landing gear of an airplane and totransfer the airplane; (ii) a sensor adapted to sense steering controlinduced movements of the landing gear or the other airplane controldevices (such as a flight control stick, throttle, pedal, steeringwheel); and (iii) a controller, connected to the sensor and to thetransfer module, adapted to receive at least one detection signal fromthe at least one sensor and in response control the transfer module.

Conveniently, the controller is further adapted to be remotelycontrolled.

Conveniently, the transfer module includes multiple independentlycontrolled wheels.

Conveniently, the unmanned airplane transfer system includes an audiointerface adapted to receive modulated audio signals representative ofsteering commands from the airplane and control the transfer module inresponse to these steering commands.

Conveniently, the system includes location sensors connected to thecontroller and the controller is adapted to control the transfer modulein response to a location of the system.

Conveniently, the controller is connected to a manual, on board, controlmodule and it is adapted to control the transfer module in response tocommands provided by the manual control module.

A method for transferring an airplane that includes: receiving atransfer signal responsive of a movement of an airplane controlcomponent; and transferring an airplane, by an unmanned airplanetransfer system, in response to the transfer signal.

Conveniently, the receiving includes sensing a movement of the airplanecontrol components and generating a transfer signal.

Conveniently, the receiving includes sensing, by an unmanned airplanetransfer system, steering control induced movements of a landing gear ofthe airplane.

A method for transferring an airplane, the method includes: (i) sensing,by an unmanned airplane transfer system, steering control inducedrotational movements of a landing gear of the airplane; and (ii)transferring an airplane, by the unmanned airplane transfer system, inresponse to the sensed steering control induced movements of a landinggear.

Conveniently, the method includes receiving control signalsrepresentative of a command to alter a velocity of the airplane andwhereas the transferring is responsive to the command.

Conveniently, the transferring is further responsive to remotelytransmitted commands.

Conveniently, the transferring includes independently controlling atleast two independently controlled wheels.

Conveniently, the method includes receiving modulated audio signalsrepresentative of steering commands and wherein the transferring isresponsive to these commands.

Conveniently, the method includes determining a location of the towedairplane and wherein the transferring system is responsive to the sensedlocation.

Conveniently, the method includes receiving commands from an operatorand wherein the transferring is responsive to the received commands.

An unmanned airplane transfer system, the system includes: a transfermodule adapted to transfer an airplane by applying skid steering; and acontroller, adapted to receive steering control signals and velocitycontrol signals and in response control the transfer module; wherein theunmanned airplane transfer system is adapted to be aligned with thelanding gear during rotational movements of the airplane.

Conveniently, the system includes a sensor adapted to sense steeringcontrol induced movements of the landing gear; and to provide thecontroller steering control signals.

Conveniently, the system is adapted to control a velocity of theairplane in response to velocity commands from the pilot.

Conveniently, the controller is further adapted to be remotelycontrolled.

Conveniently, the unmanned airplane transfer system includes an audiointerface adapted to receive modulated signals representative ofsteering commands from the airplane and to send these modulated signalsto the controller that is adapted to control the transfer module inresponse to the audio commands.

Conveniently, the system further includes location sensors coupled tothe controller, wherein the controller is adapted to control thetransfer module in response to a location of the system.

Conveniently, the controller is adapted to sense a system failure and inresponse to detach the system from the airplane.

Conveniently, the controller is connected to a manual control module andwherein the controller is adapted to control the transfer module inresponse to commands provided by the manual control module.

A method for transferring an airplane, the method includes: receivingsteering control signals and velocity control signals; and in responsetransferring the airplane by an unmanned airplane transfer system byapplying skid steering and maintaining an alignment between the unmannedairplane transfer system and the airplane during rotational movements ofthe airplane.

Conveniently, the receiving includes receiving velocity commands fromthe pilot

Conveniently, the transferring is further responsive to remotelytransmitted commands.

Conveniently, the method further includes receiving audio commands.

Conveniently, the method includes determining a location of the airplaneand wherein the transferring is responsive to the sensed location.

Conveniently, the method includes detecting an obstacle and providing anobstacle indication.

Conveniently, the method includes receiving commands from an operator, asafety driver sitting in the robot in time of emergency, duringmaintenance operations or a like, and wherein the transferring isresponsive to the received commands.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description taken in conjunction with thedrawings in which:

FIGS. 1 and 2 illustrate an airplane that is being transferred by anunmanned airplane transfer system, according to an embodiment of theinvention;

FIG. 3 illustrates an unmanned airplane transfer system, according to anembodiment of the invention;

FIG. 4 illustrates an unmanned airplane transfer system, according to anembodiment of the invention;

FIG. 5 illustrates a lower portion of a landing gear and multiplesprings and plates;

FIGS. 6-9 illustrate unmanned airplane transfer systems, according tovarious embodiments of the invention;

FIG. 10 illustrates a landing gear and an unmanned airplane transfersystem, according to various embodiments of the invention;

FIGS. 11 and 12 illustrate multiple airplanes and multiple unmannedairplane transfer systems within an airport, according to an embodimentof the invention;

FIG. 13 is a flow chart of a method for transferring an airplane,according to an embodiment of the invention;

FIG. 14 illustrates a method for controlling multiple unmanned airplanetransfer systems, according to an embodiment of the invention; and

FIG. 15 illustrates a method for transferring an airplane according toan embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

According to an embodiment of the invention an unmanned airplanetransfer system is provided. The system is controlled by one or moreairplane control component (such as a flight control stick, throttle,pedal, steering wheel) and the airplane is transferred in response tothese steering commands. An airplane control component can affect theairborne or ground movement of the airplane, especially when theairplane can autonomously move.

Conveniently, a virtual or physical movement of one or more airplanetransfer control components can be tracked, such as the flight controlstick that is used to control the airborne velocity or the groundvelocity of the airplane. It is noted that the tracking can be done byelectro-optical components, by electrical components, by adding atracking device on the control panel, within the control panel, inconnection to one of the airplanes computers and the like

Conveniently, an unmanned airplane transfer system is provided. Thesystem includes a transfer module adapted to transfer an airplane, and acontroller, connected to the transfer module, adapted to receive atransfer signal responsive of a movement of an airplane controlcomponent and in response control the transfer module.

Conveniently, the system is adapted to sense a movement of the airplanecontrol component.

Conveniently, the steering commands are sensed by a sensor adapted tosense control induced movements of the landing gear.

Pilot can control the ground movement of an airplane by using one ormore airplane transfer control components. The control can involvesending steering commands (which dictate the direction of the airplane)and velocity related commands (that dictate the speed of the airplane).

Conveniently, airplane transfer is controlled in response to mechanicalmovements of an airplane or of its landing gear. Steering commands canbe sensed by monitoring rotational movements of the landing gear aboutits axis. The system and method receive commands from the cockpit toalter the velocity of the airplane and in response can alter thevelocity of the unmanned airplane transfer system.

Conveniently, the landing gear includes a safety pin that once is stuckin the landing gear allows the landing gear to be rotated by theunmanned airplane transfer system. This safety pin is removed once theplane is about to take off. The pin removal can be done during a lastpreflight check that is also known as last minute check, in a lastminute check area. This last minute check area can also include means ofapplying fire extinguishing means and the like. It is noted that thepilot can initiate the jet engines prior to the last minute check areaand while the safety pin is still stuck in the landing gear.

According to an embodiment of the invention the unmanned airplanetransport system uses skid steering and conveniently also places thelanding gear at the geometrical center of the unmanned airplane transfersystem. Accordingly, the wheels of the unmanned airplane transportsystem are fixed, with no steering means, but their speed and optionallythe direction of their rotation can be controlled such that the wheelson one side of the system can be rotated independently from the wheelsof the other side of the system. Conveniently, the landing gear can berotated along its axes by using the skid steering. Conveniently, theunmanned airplane transfer system is aligned with the landing gearduring rotational movements of the landing gear.

Conveniently, a pilot can use the same steering control unit when beingtransferred by an unmanned airplane transfer system and when the planeautonomously moves on the ground by means of its jet engines asperformed in regular taxi. According to another embodiment of theinvention, the pilot can use the pilot flight control stick for steeringand velocity change. According to another embodiment of the inventionthe same steering control unit is used for sending controls to theunmanned airplane transfer system and while the plane autonomously moveson the ground. In both of these alternative embodiments the commands canbe sent to the unmanned airplane transfer system by wire, in a wirelessmanner and the like.

According to an embodiment of the invention the velocity of the unmannedairplane transfer system is controlled by the pilot. The control can beexecuted by using a dedicated control knob, handle, stick or device.

Conveniently, the unmanned airplane transfer system is fully automated.The unmanned airplane transfer system also can be manually controlled.Additionally or alternatively, the unmanned airplane transfer system canbe remotely controlled. A central control system can control multipleunmanned airplane transfer systems. The central control system canoptimize the taxi-in and taxi-out process of multiple airplanes.

The airplane transfer system is computer controlled and commanded from acentral control system. The central control system can track thelocations of multiple airplane transfer systems and provide visualindications to an operator. This visual and detailed presentation of thetaxi-in and taxi-out process will replace the prior art vocal basedmethod of controlling the taxi-in and taxi-out process.

Conveniently, the transfer process is fully controlled by the pilot ofthe airplane, and the unmanned airplane transfer system can transfer theairplane in a similar manner that the airplane was transferred at theabsence of the system.

Conveniently, the pilot can use a combination of steering operations inorder to send commands to the unmanned airplane transfer system.

According to another embodiment of the invention the taxi-in andtaxi-out process can be fully automated and requires no pilotintervention. The fully automation includes controlling one or moreunmanned airplane transfer systems by a central control system thatwirelessly communicates with the multiple unmanned airplane transfersystems.

The central control system can increase the safety of traffic on theground, of manned and unmanned vehicles that are positioned in theairport, and the like. The central control system can prevent conflictsamong moving entities on airport grounds: pedestrian, manned vehicles,robotic vehicles and aircraft. The central control system can alsocontrol obstacle detection and avoidance operations, traffic controlcoordination with aircraft, other vehicles and personnel, etc.

According to another embodiment of the invention an unmanned airplanetransfer system and/or the central control system can have collisionavoidance capabilities. The central control system can preventcollisions by monitoring the distance between adjacent airplanes andkeeping a certain predefined distance between airplanes. The unmannedairplane transfer system can prevent collisions by sensing the distanceof the airplane from other objects. If an object is too close theunmanned airplane transfer system can provide an audio/visual indicationand/or can alter the transfer of the airplane accordingly.

Conveniently, the unmanned airplane transfer system supports the noselanding gear. The unmanned airplane transfer system can apply any priorart method for supporting the nose landing gear. For example, it canhave a sloped surface one which the one or more wheels of the landinggear can climb.

At least the rotations of the unmanned airplane transfer system arecontrolled by the regular steering system that is used by the pilot whenthe airplane moved on the ground without being connected to the unmannedairplane transfer system. In some airplanes the steering system includesa steering wheel as well as break pedals. In other airplanes thesteering system includes a pair of pedals are used for controlling therotation and speed of the airplane.

It is noted that various wheels can be used for steering, fortransferring or a combination of both.

Conveniently, once the unmanned airplane transfer system supports thenose landing gear the airplane is transferred on its rear landing gearsand the unmanned airplane transfer system. The airplane transferringsystem can utilize skid steering thus it can rotate along its axis withsubstantially zero turning radius.

Conveniently, controlling the unmanned airplane transfer system (ATS) inresponse to movements (real or virtual) of airplane control componentdoes not require to add dedicated control panels or dedicated displays.

FIGS. 1 and 2 illustrate airplane 10 that is being transferred byunmanned airplane transfer system 100, according to an embodiment of theinvention. In FIG. 1 the airplane longitudinal axis is parallel to thelongitudinal axis of the unmanned airplane transfer system while in FIG.2 these two axes are not parallel to each other, as the unmannedairplane transfer system 100 starts to turn to the right.

FIG. 1 illustrates an airplane 10 that includes two rear landing gears12 and 14 that are positioned below corresponding wings of airplane 10.Unmanned airplane transfer system 100 also includes a nose landing gear20. The center of gravity 16 of airplane 10 is positioned between thethree landing gears 12, 14 and 20.

FIG. 2 illustrates an airplane 10 and an unmanned airplane transfersystem 100 in turning mode. The dashed line illustrates a “virtual car”where the airplane rear landing gear wheels are the “vehicle” rearwheels, and the unmanned airplane transfer system 100 is the “vehicle”front wheel, steering, velocity change, breaking and power systems.

FIG. 3 illustrates an unmanned airplane transfer system 100 according toan embodiment of the invention.

Unmanned airplane transfer system 100 includes six wheels 110(1)-110(6),engine 130, controller 160, and landing gear sensing and constrainingunits 142 and 146 and restrainers 144 and 148. The transfer module ofunmanned airplane transfer system 100 includes wheels 110(1)-110(6), theengine 130 and any mechanical transmissions used to rotate the wheels inany direction.

The landing gear sensing and constraining units 142 and 146 includesensors 142(1) and 146(1) that can sense rotational mechanical movementsof the landing gear and also include restrainers 142-148 that preventthe landing gear 20 form moving beyond relatively slight movements.

These mechanical movements at least partially occur in response tosteering commands from a pilot. Thus, if the pilot wants to turn theairplane to the right he can rotate the steering wheel to the right andthe landing gear will rotate slightly to the right. Sensors142(1)-146(1) will sense this slight movement and indicate to controller160 that the airplane should be turned to the right. Conveniently,changes in the velocity of the airplane are controlled by the pilot.

According to another embodiment of the invention system 100 alsoincludes sensors for sensing change in the velocity of the airplane sothat when the pilot hits the breaks at least the breaks of rear landinggear 12 and 14 operate to slow down the airplane. This slowing down canbe sensed by an accelerometer or can be sensed by a sensor (not shown)that is positioned between the nose landing gear and the rear landinggears.

It is noted that unique combination of steering commands (for examplesequences of rotations and/or pressing breaks) can represent transfercommands. For example a first steering command can indicate the need tospeed up the towing process. The speeding up can continue for apredefined period or until another command is sensed by system 100. Forexample, if the pilot realizes that system 100 is about to cross alanding runway he can issue a speed up command (by performing a uniquesequence of steering commands) to system 100 and in turn system 100 canspeed up the transfer process.

It is noted that unmanned airplane transfer system 100 can use variousprior art multi-direction steering technique and can include varioustypes of wheels including fixed standard wheel, steered standard wheel,castor wheel, Stanford (Swedish) wheel and the like, smart wheel(developed by the Center for Self-Organizing and Intelligent systems atthe Utah State University), and the like. It is further noted that theunmanned airplane transfer system 100 can also include one or morecaterpillar tracks or a combination of one or more caterpillar tracksand one or more wheels. A combination of wheels and caterpillar tracksis illustrated in U.S. patent application publication serial No.2006/0056949 of Eckert which is incorporated herein by reference.

Conveniently, at least two wheels out of wheels 110(1)-110(6) can rotateindependently from each other. According to another embodiment of theinvention the rotation speed of one wheel can differ from a rotationspeed of another wheel. Skid steering, for example, involves rotatingwheels on one side of the unmanned airplane transfer system 100 at aspeed that differs from the speed of the wheels at another side of theunmanned airplane transfer system 100.

It is further noted that the number of wheels can differ from six. Forexample, unmanned airplane transfer system 100 can include four wheels.The number of wheels is usually responsive to the weight of the airplaneto be towed.

Conveniently, when the airplane is towed in a straight line, thetransfer module rotates wheels 110(1)-110(6) at a constant rate.Accordingly, the airplane is constantly pulled (towed) in a manner thatresembles the slow and continuous movement of the airplane 10 when it istransferred by its idling jet engines.

It is further noted that although FIG. 1 illustrates a single motor 130but this is not necessarily so. A motor can be allocated per wheel orper group of wheels. The motor (or motors) can be connected to thewheels in various manners. For example, the unmanned airplane transfersystem can include at least one of the following: (i) diesel engine forproviding hydraulic power that drives a hydraulic motor on the wheelsvia a valve assembly; (ii) diesel engine powering an electricalgenerator and a battery that drives electrical motors that rotate thewheels; (iii) a diesel engine that both powers an hydraulic pump andalso powers an electric generator such as to drive a combination ofhydraulic motors and electrical motors; (iv) an electrical motor adaptedto receive electrical power from rails places on the surface of theairport; (v) fuel cells that drive electrical motors.

Conveniently, unmanned airplane transfer system 100 includes navigationunit 180 that enables unmanned airplane transfer system 100 to navigateat an airport. This navigation capability can be useful after unmannedairplane transfer system 100 finishes to taxi-out an airplane. Then itcan navigate itself to another airplane or to waiting point from whichit will navigate itself towards the next airplane to be towed.Navigation unit 180 can be connected to controller 160 or can be a partof controller 160. It should include at least one location sensor aswell as a storage unit that stores information representative of theairport.

Navigation unit 180 allows to navigate the airplane transfer system in afully automatic manner, in a semi-automatic manner (allows remotecontrol when an unexpected event such as a presence of a obstacleoccurs) or a fully remotely controlled manner. The remote control can beapplied by a controller of a central control unit.

It is noted that the airplane can place its landing gear on unmannedairplane transfer system by placing the unmanned airplane transfersystem at a certain location and while the unmanned airplane transfersystem is still, the pilot navigates the nose landing gear on theunmanned airplane transfer system.

FIG. 4 illustrates a rotation of a four-wheeled unmanned airplanetransfer system 101 about its axis by rotating different wheels111(1)-111(4) in different directions, while the wheels are parallel toeach other. The pilot requests to turn the plane to the left(counterclockwise) and in response the left side wheels 111(2) and111(4) are rotated clockwise while the right side wheels 111(1) and111(3) are rotated counterclockwise.

It is noted that each sensor out of sensors 142(1)-148(1) can track themovements of a spring that is connected to a plate that interfaces withthe landing gear. The springs, or alike, can be connected on their otherside to a frame. The frame and at least one plate and spring can beelevated or lowered down when the landing gear climbs on the unmannedairplane transfer system.

FIG. 5 illustrates a lower portion of a landing gear 20 and multiplesprings and plates, according to an embodiment of the invention.

Rigid frame 141 surrounds the springs and plates and prevents thelanding gear 20 from moving beyond predetermined movements. Frame 141can be lifted or raised during the placement of the landing gear onunmanned airplane transfer system 100. Frame 141 can also includedetachable frame elements that can be moved towards each other when theunmanned airplane transfer system 100 tows airplane 10.

Sensors track the movement of springs, or alike (such as springs 152 and154) that are connected to plates (such as plates 156 and 158) thatinterface with the landing gear.

Landing gear 20 is illustrated as including two wheels but the number ofwheels supported by unmanned airplane transfer system can differ thantwo.

If, for example the pilot wishes to turn to the right the landing gear20 will slightly rotate clockwise and at least some springs out ofsprings 152-154, or alike, will move accordingly.

FIG. 6 illustrates unmanned airplane transfer system 102, according toan embodiment of the invention.

Unmanned airplane transfer system 102 includes four wheels112(0)-112(4). Rear wheels 112(3) and 112(4) define an imaginary rearaxis while front wheels 112(1) and 112(2) define an imaginary frontaxis. Landing gear 20 is positioned at the geometrical center ofunmanned airplane transfer system 102, as defined by the front and rearaxes and by an imaginary longitudinal symmetry axis that is parallel tothe wheels.

FIG. 7 illustrates unmanned airplane transfer system 103, according toan embodiment of the invention.

Unmanned airplane transfer system 102 includes four wheels113(1)-113(4). Rear wheels 113(3) and 113(4) are positioned in line withthe wheels of landing gear 20. Front wheels 113(1) and 113(2) are castorwheels that can rotate along their axes. The front wheels can be usedfor steering while the rear wheels are used for towing, but this is notnecessarily so.

FIG. 8 illustrates unmanned airplane transfer system 104, according toan embodiment of the invention.

Unmanned airplane transfer system 104 includes four wheels114(1)-114(4), controller 160 and transceiver 165. The transceiver 165is adapted to receive commands over a wireless medium. These commandsare sent to controller 160 that in turn can control unmanned airplanetransfer system 104 in response to these commands. It is noted thatunmanned airplane transfer system 104 can operate in multiplemodes—pilot controlled mode, remote control mode and a hybrid mode inwhich various commands can be provided in a remote manner while othercommands are sensed by at least one landing gear sensing andconstraining unit, and also manual (local) driving by and operator.

It is noted that the unmanned airplane transfer system can alsocontrolled by a short-range remote control transmissions, by using a laptop computer and the like.

Conveniently, unmanned airplane transfer system 104 included optionalposition sensors such as but not limited to GPS based sensors thatenable to determine the location of the system. The location of system104 can affect the movements of the system. For example, if the systemis about to cross a landing runway then system 104 can speed up thetransfer process. The speeding up can include increasing the speed to apredefined speed and lowering the speed once the airplane passes thelanding runway. The locations of the landing runways can be previouslyprovided to system 104. According to another embodiment of the inventionthe velocity is only controlled by the pilot.

Conveniently, unmanned airplane transfer system 104 includes optionalobstacle unit 118 adapted to detect and/or avoid obstacles.

Obstacle unit 118 can include one or more obstacle sensors such as alaser scanner, a radar, a camera, an acoustic sensor or a combinationthereof. The obstacle sensor can scan the area in front of airplane 100or especially in front of unmanned airplane transfer system 104 in orderto detect obstacles. If an obstacle is detected the unmanned airplanetransfer system 104 is stopped by the pilot, or it can alter the path ofthe towed airplane, provide an audio/visual indication (includingactivating a siren), sending an indication to a central control systemand the like.

According to an embodiment of the invention once an obstacle is detecteda central control system is informed and the airplane transfer systemcan acknowledge a change of path or request the pilot to select whetherto change the path. The path change can be controlled by the pilot, bythe central control system and optionally by the airplane transfersystem.

FIG. 9 illustrates unmanned airplane transfer system 105, according tovarious embodiments of the invention.

Unmanned airplane transfer system 105 includes four wheels115(1)-115(4), controller 160, transceiver 165 and a manual controlinterface 167. Manual control interface 167 can allow an operator tomanually operate unmanned airplane transfer system 105. It can include asteering wheel, a pedal and the like.

It is noted that an unmanned airplane transfer system can include both atransceiver and a manual control interface and that such a system canoperate in multiple different operational modes.

FIG. 10 illustrates unmanned airplane transfer system 100 and a landinggear 20 according to an embodiment of the invention.

Unmanned airplane transfer system 100 is adapted to receive modulatedsignals representative of steering commands over an audio connection.These modulated signals are generated in response to pilot steeringefforts as well as pilot control of the velocity of the airplane.

Conveniently, the audio link is used for conveying audio commands fromthe pilot. Unmanned airplane transfer system 105 can apply voicerecognition techniques in order to recognize these audio commands. Oncea command is recognized the unmanned airplane transfer system canoperate according to the command.

It is noted that the reception of audio commands or of the modulatedsignals representative of steering commands can replace the sensing ofmechanical movements but can also be applied in addition to the sensingof the mechanical movements of the landing gear.

According to yet another embodiment of the invention the connection tothe audio plug can be done by an operator.

Typically such audio output interfaces are found in airplanes that weretowed by manned towing vehicles.

It is noted that the connection to the audio output interface can bedone automatically by using a camera and applying image recognition toguide an interface of the unmanned airplane transfer system towards theaudio output interface of the landing gear.

FIG. 10 illustrates camera 191, gripper 192, sliding audio plug 193, andsliding audio cover lifter 194 that are connected to a movable arm 195.Movable arm can lift the camera 191 to the height of the audio outputinterface 21 of landing gear 20, use enable sliding gripper 194 to holdlanding gear 20, allow the sliding audio cover lifter to lift a coverthat protects audio output interface 21 and then enable the slidingaudio plug 193 to connect to audio output interface 21.

Conveniently, movable arm 195 can be used to remove the nose landinggear wheel safety pin, in accordance to the transferring system mode ofoperation and according to the towing phase.

FIG. 11 illustrates multiple airplanes 10(1)-10(8) and multiple unmannedairplanes transfer systems 100(1)-100(10) according to an embodiment ofthe invention.

The multiple airplanes 10(1)-10(11) and multiple airplanes transfersystems 100(1)-100(10) are located at airport 200.

Airport 200 includes terminal 210, take-off runway 262, check up area261, unmanned airplane transfer system path 266 and taxi-out area 264.

Conveniently, a last minute check is performed at check-up area 261, byan operator that checks the airplane for leaks, can extinguish fire, canremove the safety pin that allows the landing gear to be rotated and thelike. The airplane can ignite their jet engines at check up area 261 orbefore reaching that area. For Example, airplanes 10(2), 10(3) and even10(4) can ignite their engines. An unmanned airplane transfer system candetach from the airplane before reaching check-up area 261.

In addition, FIG. 12 illustrates a central control system 250 that iscapable of communicating with airplanes transfer systems 100(1)-100(10)and controlling their movements.

Airplane 10(1) is positioned at engine start and check up area 216 afterbeing disconnected form the unmanned airplane transfer system that towedit from terminal 210. Unmanned airplane transfer systems such as systems100(9), 100(10) and 100(1) that completed their task return to terminal210, via unmanned airplane transfer system path 266.

Airplanes 10(2)-10(8) are being towed, at taxi-out area 268, by unmannedairplane transfer systems 100(2)-100(8). Airplane 10(5) waits atterminal 210 to be towed by an unmanned airplane transfer system.

Conveniently, the airplane stops before the unmanned airplane transfersystem detaches from it. After the towing ends the unmanned airplanetransfer system can navigate towards the terminal. The navigation aswell as the towing can be at least partially controlled by centralcontrol system 250, but this is not necessarily so.

According to an embodiment of the invention the central control system250 is a C⁴ command and control system. It is operated by the AirportTaxi Supervisor/Ground Traffic Controller operator. Central controlsystem 250 can control multiple airport transfer systems. It canoverride manually controlled unmanned airplane transfer systems, canoverride steering mechanism based upon sensing airplanes movements andthe like. It can optimize the movements of unmanned airplane transfersystems, either during towing operation or during transfer betweenpositions without airplanes. Central control system 250 can beintegrated with the airport air traffic control system.

The central control system 250 can track the location of the variousairplane transfer systems (by receiving location information from theairplane transfer systems, from the planes, from other locationsensors), and displays to a controller the location of the variousairplanes, airplane transfer system and thus greatly reduced humanerrors in the taxi-in and taxi-out process. Conveniently the centralcontrol system also received location information (either directly orvia another control system) of various vehicles that are present in theairport and especially near runways and in the taxi-in and taxi-outareas and can provide to the controller an overall visual representationof the airport and the various entities in the airport. The centralcontrol system 250 can prevent aircraft taxi accidents, vehicle-aircraftaccidents. It can prevent pilot or traffic controller errors andmisunderstandings towards take-off, and the like.

Central control system 250 includes: (i) At least one transmitter (suchas transmitter 252) adapted to transmit steering commands to multipleunmanned airplane transfer vehicles. (ii) At least one receiver (such asreceiver 254) adapted to receive location information from the multipleunmanned airplane transfer vehicles. (iii) At least one display (such asdisplay 256) for displaying locations of multiple airplanes and themultiple unmanned airplane transfer vehicles. (iv) At least oneinterface (such as interface 258) adapted to receive from an operatoroperational mode commands adapted to determine a control mode of atleast one unmanned air plane transfer system. The interface can includekeyboard, mouse, and the like that are connected to a computer that inturn controls display 256.

Conveniently, central control system 250 is adapted to receive anobstacle indication from an unmanned airplane transfer system and toselectively acknowledge a change in a path of the unmanned airplanetransfer system.

Conveniently, central control system 250 is adapted to receive anobstacle indication from an unmanned airplane transfer system and tocontrol a change of path of the unmanned airplane transfer system.

Conveniently, central control system 250 is adapted to receive a failureindication from an unmanned airplane transfer system and to selectivelyacknowledge a detachment of the unmanned airplane transfer system fromthe airplane.

Conveniently, central control system 250 is adapted to receive a failureindication from an unmanned airplane transfer system and to control atransfer of an airplane by the unmanned airplane transfer system.

Conveniently, central control system 250 is adapted to optimize adistance between multiple airplanes being towed by multiple unmannedtransfer systems.

Conveniently, central control system 250 can control an unmannedairplane transfer system in a first operational mode in which centralcontrol system sends 250 steering commands that override steeringcommands that are mechanically sensed by the unmanned airplane transfersystem.

FIG. 12 illustrates multiple airplanes 10(1)-10(5) and multipleairplanes transfer systems 100(1)-100(8) according to an embodiment ofthe invention.

The multiple airplanes 10(1)-10(5) and multiple airplanes transfersystems 100(1)-100(8) are located at airport 200.

Airport 200 includes terminal 210, landing runway 212, landing pickuparea 218 and unmanned airplane transfer system path 214. A centralcontrol system 250 is also located in airport 200. Airplane 10(5) islanding on landing runway 212. Airplane 10(4) has previously landed andis approached by unmanned airplane transfer system 100(5). Airplane10(3) is towed by unmanned airplane transfer system 100(3) towardsterminal 210. Airplane 10(2) is towed by unmanned airplane transfersystem 100(2) towards terminal 210. Airplane 10(1) was towed by unmannedairplane transfer system 100(1) and is hooked to terminal 210 at thegate.

Unmanned airplane transfer systems 100(6)-100(8) propagate throughunmanned airplane transfer system path 214, towards landing pickup area218. Unmanned airplane transfer system 100(4) waits, at landing pickuparea 218, to airplane 10(4).

Conveniently, the airplane stops before being towed, to enable theunmanned airplane transfer system to support its landing gear. After thetowing ends at the engine start and check up area, the unmanned airplanetransfer system can navigate towards the landing pickup area 218. Thisnavigation can be controlled by a central control system, but this isnot necessarily so.

FIG. 13 illustrates method 300 for transferring an airplane, accordingto an embodiment of the invention.

Method 300 starts by stage 310 of receiving a landing gear by anunmanned airplane transfer system.

Stage 310 is followed by stage 320 of sensing, by an unmanned airplanetransfer system, steering control induced movements of a landing gear ofthe airplane. Referring to the example set fourth in FIGS. 3 and 5multiple sensors sense rotational mechanical movements of the mechanicalgear such as rotation, de-acceleration and the like.

Stage 320 is followed by stage 330 of transferring an airplane, by theunmanned airplane transfer system, in response to the sensed steeringcontrol induced movements of a landing gear. Referring to the examplesset fourth in FIGS. 1-4 and 9, the airplane is towed by an unmannedairplane towing system in response to the sensed movements.

Stage 330 is followed by stage 340 of detaching the airplane from theunmanned airplane transfer system. Referring to the example set fourthin FIGS. 11 and 12, once the taxi-in or taxi-out is completed theunmanned airplane transfer system can detach.

Conveniently, stage 320 of sensing includes sensing pilot commands todetermine the airplane velocity whereas the transferring is responsiveto the velocity change commands.

Conveniently, stage 330 of transferring is further responsive toremotely transmitted commands. Referring to the examples set fourth inFIGS. 8,9 and 12 the unmanned airplane transfer system can include atransceiver for receiving commands and it can be remotely controlled bya central control system although this is not necessarily so.

Conveniently, stage 330 of transferring includes independentlycontrolling at least two independently controlled wheels. Referring tothe example set fourth in FIGS. 7 and 4, different wheels can rotate atdifferent speeds, at different directions and can also be placed inpositioned that are not parallel to each other.

Conveniently, method 300 also includes receiving audio commands ormodulated signals representative of steering commands and wherein thetransferring is responsive to the received audio commands. Referring tothe example set fourth in FIG. 10, the unmanned airplane transfer systemcan receive audio commands from the landing gear, recognize the commandsand act accordingly.

Conveniently, method 300 also includes determining a location of theairplane and wherein the transferring is responsive to the sensedlocation.

Conveniently, method 300 further includes detecting an unmanned airplanetransfer system failure and in response detaching the airplane from theunmanned airplane transfer system.

It is noted that once a failure is detected the unmanned airplanetransfer system can allow the central control system to take control.The central control system can select to detach the airplane transfersystem, but this is not necessarily so. It is further noted that thedetachment can be responsive to the type of failures. For example,failures that prevent the unmanned airplane transfer system to becontrolled by the central control system may require a detachmentwithout the interference of the control system. Yet according to anotherembodiment of the invention the pilot can try to control the unmannedairplane transfer system, for example, by sending audio commands.

Conveniently, method 300 includes detecting an obstacle and stage 330 oftransferring is responsive to a detected obstacle.

Conveniently, method 300 includes receiving commands from an operatorand stage 330 of transferring is responsive to the received commands.

FIG. 14 illustrates method 400 for controlling multiple unmannedairplane transfer systems, according to an embodiment of the invention.

Method 400 starts by stage 410 of receiving location information frommultiple unmanned airplane transfer systems. Stages 410 is followed bystage 420 of displaying locations of multiple airplanes and the multipleunmanned airplane transfer vehicles.

Stage 420 is followed by stage 430 of receiving from an operator anoperational mode command that determines an operational mode of anunmanned airplane transfer system.

Stage 430 is followed by stage 440 of transmitting the operational modecommand to the unmanned airplane transfer system.

Stage 440 is followed by stage 450 of sending steering commands to anunmanned airplane transfer system, if a remote controlled operationalmode was selected. The selection can be made by a central control systemoperator. Stage 450 includes sending steering commands that overridesteering commands that are mechanically sensed by the unmanned airplanetransfer system.

Method 400 can also include stage 460 of receiving, by a central controlsystem, an obstacle indication from an unmanned airplane transfersystem. Stage 460 can be followed by stage 462 of selectivelyacknowledging a change in a path of the unmanned airplane transfersystem. Stage 460 can. Alternatively or additionally, followed by stage464 of controlling a change of path of the unmanned airplane transfersystem.

Method 400 can also include stage 470 of receiving, by a central controlsystem, a failure indication from an unmanned airplane transfer system.Stage 470 can be followed by stage 472 of selectively acknowledging adetachment of the unmanned airplane transfer system from the airplane.Stage 470 can also be followed by stage 474 of controlling a transfer ofan airplane by the unmanned airplane transfer system.

Method 400 can also include stage 480 of optimizing a distance betweenmultiple airplanes being towed by multiple unmanned transfer systems.This optimization can include positioning the airplanes close to eachother but at a distance that will not dramatically increase theprobability of collisions between airplanes.

FIG. 15 illustrates method 500 for transferring an airplane, accordingto an embodiment of the invention.

Method 500 starts by stage 310 of receiving a landing gear by anunmanned airplane transfer system.

Stage 310 is followed by stage 520 of receiving a transfer signalresponsive of a movement of an airplane control component. Stage 520 caninclude stage 320 but can include, alternatively or additionally,receiving (over wire or in a wireless manner) a transfer signal from anairplane control component, tracking the movement of an airplane controlcomponent and the like.

Stage 520 is followed by stage 530 of transferring an airplane, by anunmanned airplane transfer system, in response to the transfer signal.Stage 530 can include stage 330 but this is not necessarily so.

Stage 530 is followed by stage 340 of detaching the airplane from theunmanned airplane transfer system.

According to an embodiment of the invention the status of the unmannedairplane transfer system can be reported to the pilot or to a centralcontrol system or both. Conveniently, the pilot can receive statusindications while the airplane is being transferred to the unmannedairplane transfer system and the central control system can receivestatus indications when the unmanned airplane transfer system is notattached to the landing gear of the airplane.

Variations, modifications, and other implementations of what isdescribed herein will occur to those of ordinary skill in the artwithout departing from the spirit and the scope of the invention asclaimed. Accordingly, the invention is to be defined not by thepreceding illustrative description but instead by the spirit and scopeof the following claims.

1. An unmanned airplane transfer system, comprising: a transfer moduleadapted to transfer an airplane; and a controller, coupled to thetransfer module, adapted to receive a transfer signal responsive of amovement of an airplane control component and in response control thetransfer module.
 2. The system according to claim 1 wherein the unmannedairplane transfer system comprises a sensor adapted to sense a steeringcontrol induced movement of the landing gear and in response provide atransfer signal to the controller.
 3. The system according to claim 1whereas the system is adapted to sense a movement of the airplanecontrol component.
 4. The system according to claim 1 whereas the systemis adapted to control a velocity of the airplane in response to avelocity signal.
 5. The system according to claim 1 whereas thecontroller is further adapted to be remotely controlled.
 6. The systemaccording to claim 1 whereas the transfer module comprises multipleindependently controlled wheels.
 7. The system according to claim 1whereas the unmanned airplane transfer system comprises an audiointerface adapted to receive modulated signals representative ofsteering commands from the airplane and to send these modulated signalsto the controller that is adapted to control the transfer module inresponse to the audio commands.
 8. The system according to claim 1further comprising location sensors coupled to the controller, whereinthe controller is adapted to control the transfer module in response toa location of the system.
 9. The system according to claim 1 wherein thecontroller is adapted to sense a system failure and in response todetach the system from the airplane.
 10. The system according to claim 1wherein the controller is coupled to a manual control module and whereinthe controller is adapted to control the transfer module in response tocommands provided by the manual control module.
 11. The system accordingto claim 1 wherein the system is adapted to be aligned with the landinggear during rotational movements of the airplane.
 12. The systemaccording to claim 1 wherein the system comprises a skid steeringtransfer module.
 13. A method for transferring an airplane, the methodcomprises: receiving a transfer signal responsive of a movement of anairplane control component; and transferring an airplane, by an unmannedairplane transfer system, in response to the transfer signal.
 14. Themethod according to claim 13 wherein the receiving comprises sensing amovement of the airplane control components and generating a transfersignal.
 15. The method according to claim 13 wherein the receivingcomprises sensing, by an unmanned airplane transfer system, steeringcontrol induced movements of a landing gear of the airplane.
 16. Themethod according to claim 13 whereas the transferring is furtherresponsive to remotely transmitted commands.
 17. The method according toclaim 13 whereas transferring comprises independently controlling atleast two independently controlled wheels.
 18. The method according toclaim 13 further comprising receiving audio commands and wherein thetransferring is responsive to the received audio commands.
 19. Themethod according to claim 13 further comprising determining a locationof the airplane and wherein the transferring is responsive to the sensedlocation.
 20. The method according to claim 13 further comprisingdetecting an obstacle and provide an obstacle indication.
 21. The methodaccording to claim 13 further comprising receiving commands from anoperator and wherein the transferring is responsive to the receivedcommands.
 22. The method according to claim 13 wherein the transferringcomprises applying skid steering.
 23. The method according to claim 13wherein the transferring comprises maintaining an alignment between theunmanned airplane transfer system and the landing gear of the airplaneduring rotational movements of the airplane.
 24. A central controlsystem comprising: at least one transmitter adapted to transmit steeringcommands to multiple unmanned airplane transfer vehicles; at least onereceiver adapted to receive location information from the multipleunmanned airplane transfer vehicles; at least one display for displayinglocations of multiple airplanes and the multiple unmanned airplanetransfer vehicles; and at least one interface adapted to receive from anoperator operational mode commands adapted to determine a control modeof at least one unmanned air plane transfer system.
 25. The centralcontrol system according to claim 24 wherein the central control systemis adapted to receive an obstacle indication from an unmanned airplanetransfer system and to control a change of path of the unmanned airplanetransfer system.
 26. The central control system according to claim 24wherein the central control system is adapted to receive a failureindication from an unmanned airplane transfer system and to selectivelyacknowledge a detachment of the unmanned airplane transfer system fromthe airplane.
 27. The central control system according to claim 24wherein the central control system is adapted to receive a failureindication from an unmanned airplane transfer system and to control atransfer of an airplane by the unmanned airplane transfer system. 28.The central control system according to claim 24 further adapted tooptimize a distance between multiple airplanes being towed by multipleunmanned transfer systems.
 29. The central control system according toclaim 24 wherein in a first operational mode the central control systemsends steering commands that override steering commands that aremechanically sensed by the unmanned airplane transfer system.
 30. Amethod for controlling multiple unmanned airplane transfer systems, themethod comprises: receiving location information from multiple unmannedairplane transfer systems; displaying locations of multiple airplanesand the multiple unmanned airplane transfer vehicles; receiving from anoperator an operational mode command that determines an operational modeof an unmanned airplane transfer system; and transmitting theoperational mode command to the unmanned airplane transfer system. 31.The method according to claim 30 wherein the method comprises receiving,by a central control system, an obstacle indication from an unmannedairplane transfer system and selectively acknowledging a change in apath of the unmanned airplane transfer system.
 32. The method accordingto claim 30 wherein the method comprises receiving, by a central controlsystem, an obstacle indication from an unmanned airplane transfer systemand controlling a change of path of the unmanned airplane transfersystem.
 33. The method according to claim 30 the method comprisesreceiving, by a central control system, a failure indication from anunmanned airplane transfer system and selectively acknowledging adetachment of the unmanned airplane transfer system from the airplane.34. The method according to claim 30 wherein the method comprisesreceiving, by a central control system, a failure indication from anunmanned airplane transfer system and controlling a transfer of anairplane by the unmanned airplane transfer system.
 35. The methodaccording to claim 30 further comprising optimizing a distance betweenmultiple airplanes being towed by multiple unmanned transfer systems.36. The method according to claim 30 further comprising sending steeringcommands that override steering commands that are mechanically sensed bythe unmanned airplane transfer system.
 37. An unmanned airplane transfersystem, comprising: a transfer module adapted to transfer an airplane byapplying skid steering; and a controller, adapted to receive steeringcontrol signals and velocity control signals and in response control thetransfer module; wherein the unmanned airplane transfer system isadapted to be aligned with the landing gear during rotational movementsof the airplane.
 38. The system according to claim 37 further comprisinga sensor adapted to sense steering control induced movements of thelanding gear; and to provide the controller steering control signals.39. The system according to claim 37 whereas the system is adapted tocontrol a velocity of the airplane in response to velocity commands fromthe pilot.
 40. The system according to claim 37 whereas the controlleris further adapted to be remotely controlled.
 41. The system accordingto claim 37 whereas the unmanned airplane transfer system comprises anaudio interface adapted to receive modulated signals representative ofsteering commands from the airplane and to send these modulated signalsto the controller that is adapted to control the transfer module inresponse to the audio commands.
 42. The system according to claim 37further comprising location sensors coupled to the controller, whereinthe controller is adapted to control the transfer module in response toa location of the system.
 43. The system according to claim 37 whereinthe controller is adapted to sense a system failure and in response todetach the system from the airplane.
 44. The system according to claim37 wherein the controller is coupled to a manual control module andwherein the controller is adapted to control the transfer module inresponse to commands provided by the manual control module.
 45. A methodfor transferring an airplane, the method comprises: receiving steeringcontrol signals and velocity control signals; and in responsetransferring the airplane by an unmanned airplane transfer system byapplying skid steering and maintaining an alignment between the unmannedairplane transfer system and the airplane during rotational movements ofthe airplane.
 46. The method according to claim 45 whereas the receivingcomprises receiving velocity commands from the pilot
 47. The methodaccording to claim 45 whereas the transferring is further responsive toremotely transmitted commands.
 48. The method according to claim 45further comprising receiving audio commands.
 49. The method according toclaim 45 further comprising determining a location of the airplane andwherein the transferring is responsive to the sensed location.
 50. Themethod according to claim 45 further comprising detecting an obstacleand provide an obstacle indication.
 51. The method according to claim 45further comprising receiving commands from an operator and wherein thetransferring is responsive to the received commands.